The second plot line of "Mahjong 2" is about the authenticity of the riverside scene on Qingming Festival. In fact, Zhang Zeduan, a court painter, was not very famous when he created The Riverside Scene at Qingming Festival. Although he was also a court painter in the Song Dynasty, he was not famous. Silk used for painting is a common monofilament. At that time, only famous senior painters could use double silk, which was also recognized by Wu Mai and Bai Ruilian, and so was Bai Ruilian's The Riverside Scene at Qingming Festival.

In fact, the Forbidden City version of The Riverside Scene at Qingming Festival is nearly one third less. Dai Haiyan, a doctor of biology who teaches at the university, told Wish that the missing part of the Riverside Map at Qingming Festival should draw Jinming Pool and Xishuimen, which were landmark buildings at that time. Since Song Huizong asked the court painter Zhang Zeduan to paint the capital of song dynasty, there should be no shortage of these two places. Most importantly, Song Huizong's inscription and Shuanglong Xiaoyin were all gone, so Dai Haiyan guessed that there were some fragments of the Riverside Map at Qingming Festival, and made a wish to find some ways to find the fragments of the Riverside Map at Qingming Festival, and finally found the key material evidence-Shuanglong Xiaoyin fragments.

At the scene of Jianbao in Hong Kong, I took the key evidence of Shuanglong Xiaoyin and made a wish to face two versions of Riverside Scene at Qingming Festival. After careful identification, I found that the silver fragment of Shuanglong in Song Huizong in my hand is double-filament, which is consistent with Berry Lian's version of The Riverside Scene at Qingming Festival, while the Palace Museum's version of The Riverside Scene at Qingming Festival is single-filament, which means that the silver fragment of Shuanglong is the same as Berry Lian's version. Zhu Rong knew that if he told the truth, it would be extremely unfavorable to the Forbidden City edition, but all he could think about was to discard the false and keep the true, stick to the principle and tell his true judgment.

When I made a wish that the fragment of Shuanglong Silver was in the same strain as Bai Ruilian's version of The Riverside Scene at Qingming Festival, I thought I lost. Unexpectedly, the situation was reversed. It turned out that Chen of Bairuilian stated in advance at the scene that if there was a fragment of Ssangyong, it must be a fake made by a counterfeiter on purpose. Therefore, eight experts at the scene agreed that the picture scroll that can match the debris must be a fake. In this way, Bai Ruilian's version of The Riverside Scene at Qingming Festival, which is homologous to the fragment, is a fake after the funeral, and the Riverside Scene at Qingming Festival in the Forbidden City is the real national treasure.